Toy sewing machine



April 1968 SHIGEAKI KURAMOCHI 3,380,413

TOY SEWING MACHINE Filed Oct. '13, 1965 2 Sheets-$heet 1 DRY BATTERY 5.0'VDC MOTOR All? sesame FOOT PEDAL SWITCH CONSENT OVER 1 SWITCH US) i on" OFF orT'bFF INVEN T R FOOT SWITCH SWITCH (l8) BY 3Z4 April 1968 SHIGEAKI KURAMOCHI 3,380,413

TOY SEWING MACHINE Filed Oct. 15, 1965 '3 Sheets- Sheet 2 FIG. 2

INVENTOR BYMW United States Patent 3,380,413 TOY SEWING MACHINE Shigealri Knramochi, 24-17 Koishikawa S-chome,

Bnnkyo-ku, Tokyo, Japan Filed Oct. 13, 1965, Ser. No. 495,456 2 (Ilaims. (Cl. 1121) ABSTRACT OF THE DISCLOSURE A toy sewing machine capable of carrying out sewing in the same manner as a real sewing machine having a changeover switch changing over an electric motor to rotate positively or reversely, and a free-wheeling mechanism provided between a spindle carrying a handle for hand rotation thereof and a transmission system, whereby the spindle rotates in the desired direction when the electric motor rotates in the positive direction, and the spindle does not rotate when the motor rotates in the reverse direction.

The present invention relates to a toy sewing machine.

Conventional toy sewing machines have had the disadvantage of lacking in facilities for actual sewing or of lacking in sewing efiiciency or of being apt to go wrong due to the fact that they have mostly been simple miniatures from which some of mechanisms of real sewing machines are omitted.

The primary object of the present invention is to eliminate all disadvantages of conventional toy sewing machines and to provide a novel toy sewing machine by which sewing can be completely carried out as well as by a real sewing machine.

Another object of the present invention is to provide a toy sewing machine which is driven by an electric motor and which can stitch efiiciently.

Still another object of the present invention is to provide a toy sewing machine of the remote control type which can be driven by hand and which can also be controlled by a pedal switch placed at the foot of an operator when the machine is set on a table.

Further objects and advantages of the present invention will be clear from the following specification, taken with the accompanying drawings in which:

FIG. 1 is a front perspective view of an embodiment of the toy sewing machine according to the present invention and viewed from the position of an operator;

FIG. 2 is an elevation view of the opposite side of the machine of FIG. 1 with the head cover removed and a part of the bed being broken away in order to show the internal mechanisms therein;

FIG. 3 is an end elevation view, viewed from the end with the bobbin case;

FIG. 4 is a partial sectional end view from the motor end with the hand wheel removed to show the gear mechanism for driving a spindle; 7

FIG. 5 is an enlarged partial perspective view showing the reciprocating mechanism of a needle rod;

FIG. 6 is a wiring diagram that shows the wiring connecting a dry cell, a motor and switches.

It should be noted that in each drawing the same reference numerals are used to indicate the same parts.

(I) DRIVING OF A SPINDLE A spindle-driving mechanism and a sewing mechanism are placed in the inner cavity of a head 3 of diecast light metal which is mounted on a bed 1 made of steel plate. First, the driving of a spindle 33 will be explained. When a change-over switch 19 is placed in a SEWING position and an actuating switch 18 in the ON position, an electric current flows to a motor M from a dry cell (two dry cells of 1.5 v. in this embodiment), and the main shaft of the motor M accordingly begins to rotate a drive pinion 26 directly connected to the shaft in the clockwise direction as indicated by the arrow in FIG. 4. Turning of the drive pinion 26 causes a pinion 27 engaged with the pinion 26 to turn in the counter-clockwise direction, and pinion 28 to drive a main gear 29 in the clockwise direction.

At one end of the spindle 33 is fixed a cylindrical bushing 32, the outer periphery of which engages with the inner periphery of the hub portion of a hand wheel 4. At intervals of a quarter of the inner circumference of the hub are formed four radially extending recessed portions 30 each of which has therein a steel ball 31 through which the hand wheel 4 engages with the outer circumferential surface of the bushing 32.

Each recess 38! defines together with the outer periphery of the bushing 32 a confined space and the radial dimension of these recesses decreases to zero at the circumferential extremity of the recesses as clearly shown in FIG. 4. It should be noted that this mechanism is a kind of a well known free-wheeling connection, in which when the main gear 29 rotates in the clockwise direction, the bushing 32 also rotates in the same direction, whereas the bushing 32 does not turn when the main gear 29 rotates in the counter-clockwise direction. On the other hand, the main gear 29 does not rotate when the bushing 32 is rotated in the clockwise direction. When the change-over switch 19 is set in a SEWING position, the main gear 29 rotates in the clockwise direction in FIG. 4 and the spindle 33 also rotates in the same direction. On the other hand, when the changeover switch 19 is placed in the BOBBIN position, the main gear 29 rotates in the counter-clockwise direction without rotating the spindle 33.

The spindle 33 extends horizontally within the head 3 and a cam wheel 43 is fixed on its other end.

Midway of the spindle 33 is eccentrically fixedly mounted a circular dish-shaped gear 34 which meshes with a cylindrical gear 35 mounted on the upper end of a shaft 36 extending vertically and in a direction perpendicular to that of the spindle 33. On the lower end of the vertical shaft 36 is also fixedly mounted a cylindrical gear 37 (of the same shape as the gear 35) which meshes with a circular dish-shaped gear 38 (of the same shape as the gear 34) fixedly mounted on an end of a shaft 39 extending horizontally in the bed 1. Since the circular dishshaped gear 34 is eccentrically mounted on the spindle 33, the position of engagement with the cylindrical gear 35 moves toward and away from the axis of the spindle as it rotates. This combination of two gears is sometimes spoken of as a mechanism for producing variable circular motion. However, the position of engagement between the circular dish-shaped gear 34 and the cylindrical gear 35 is selected so that it is just the opposite to the position of engagement between the circular dish-shaped gear 38 and the cylindrical gear 37, so that the horizontal shaft 39 in the bed 1 rotates at the same constant speed as the spindle 33.

The reason why such a mechanism producing variable circular motion of shaft 36 is used instead of an ordinary mechanism consisting of bevel gears carried on perpendicular shafts is as follows. Firstly, since the teeth on the circular dish-shaped gears 34 and 38 are rack-shaped teeth and can therefore be easily manufactured by diecasting of light metals, and since the cylindrical gears 35 and 37 can also be easily made by moulding of synthetic resins, these parts of the present toy machine can be manufactured at a lower cost then bevel gears.

Secondly, the cylindrical gear is not easily worn out because of its relatively wide area of engagement with the dish-shaped gear, and engaging noise can be reduced because the gear is made of synthetic resin.

On the other end of the shaft 39 is mounted a bobbin case 42.

If the sewing machine is to be driven by hand, the hand wheel 4 can be turned by a handle 17 in the clockwise direction viewed from the left side in FIG. 2. At this time the main gear 29 does not move, the balls 31 rotating freely in the recesses 30. The handle 17 consists of a handle knob and a handle lever 17 pivotally mounted on the periphery of the hand wheel 4 and extending radially. The handle lever 17 can be positioned in the hub of the hand wheel 4, so that the projecting handle lever does not obstruct the rotation of the hand wheel when the sewing machine is to be driven by electricity.

(II) MOVEMENT OF NEEDLE Referring to FIGS. 2, 3 and 5, a cam wheel 43 consists of a central cylindrical body 44 extending in the same direction as the spindle 33 and an outer cylindrical memher coaxially surrounding the central body. A configuration is formed on the peripheral wall of the outer cylindrical member with differences in axial height of the wall and this serves as a cam surface 45. A thread take-up lever 9 is pivotally mounted at the elbow thereof on the head 3 on a screw 43, and a pin 47 fixed on the other end of the lever 9 serves as a cam follower engaging with said cam surface 45. Above the pivotal screw 48 is mounted a return spring 49 of suitable material such as Phosphor bronze which is positioned to engage the thread take-up lever 9 when it is raised as the cam wheel 43 rotates and to urge the thread take'up lever down into engagement with the cam surface 45.

On the end surface of the central cylindrical body 44 is secured a radially extending crank plate 50, the end of which carries a crank pin 50' extending parallel to the spindle 33 (FIG. 2). On the other hand, a cam plate 51 is fixed by a screw 53 to a vertical needle rod slidably mounted in the head 3, and a cam slot 52 (FIGS. 3 and 5 provided in the cam plate 51 engages with said crank pin 50. These camming parts 50' and 52 are constructed so as to reciprocate the needle rod 5 up and down as the cam wheel 43 rotates. This provides the sewing motion of a needle 16 fixed on the needle rod by means of a needle set screw 14.

A presser rod 54 is slidably mounted in the head 3 parallel to the needle rod 5. At the lower end of the presser rod 54 is mounted a presser foot 6 which is biased toward the upper surface of the bed 1 by a presser spring 55 around the presser rod 54, As clearly shown in FIG. 5, the presser rod 54 is also provided with a L-shaped presser lever 56 pivotally mounted thereon. The presser foot 6 can be kept spaced from the surface of the bed by raising the presser lever 56 and accordingly the presser rod 54. Sewing materials can be placed in position or removed from beneath the needle with the presser foot 6 in the raised position.

(III) BOBBIN CASE AND CLOTH FEEDING On the end of the shaft 39 extending horizontally in the bed 1 is fixed a bobbin case 42 of a hollow conical shape, a part of which has a sewing hook 58 thereon as shown in FIG. 3. The bobbin case 42 has a circular recess which receives a bobbin 57 therein.

Said recess of the bobbin case has a slot (not shown) which is adapted to engage with a bobbin case latch 57 in order to set the bobbin case 57. The bobbin can be easily set by fitting the latch 57' into the slot and thereafter turning the latch to the horizonal position as shown in FIG. 3.

When the electric motor M rotates in the direction of SEWING" the horizontal shaft 39 rotates in the counterclockwise direction in FIG. 3 with the result that the bobbin case 42 rotates in the same direction. The rotating motion of the bobbin case 42 is regulated so that the sewing hook 58 can intersect the needle 16 in juxtaposition thereto just before the needle 16 moves upwardly off the upper surface of the bed 1 during the upward motion of the needle.

Feeding of materials being sewn is done by a material feeding plate. The material feeding plate has two plate portions perpendicular to each other; one of them being vetrical plate portion 6% and the other being a horizontal plate portion 60' with feeding teeth 62 (FIGS. 1 and 2) projecting slightly above the surface of the bed. In the vertical plate portion 60 has a horizontally extending aperture (not shown) which engages with an elliptical cam portion (not shown) eccentrically provided at the end of the horizontal shaft 39. The material feeding plate portion 66 is also pivotally guided by a pin 61 near the edge of the plate and is biased by a tension spring 63 rightwards in FIG. 3. With this mechanism, as the shaft 39 turns the material feeding plate 69, 60' is first moved upwards, then forward (leftwards in FIG. 3) and is returned when the cam engagement between the vertical plate portion 60 and the shaft 39 ends. Consequently, the feeding teeth 62 provided on the horizontal plate portion 60' of the feeding plate perform material feeding motion such as mentioned above.

A distance which the plate portion 60' is moved forward by one turn of the shaft 39, namely, the length of one stitch, can be adjusted by a stitch regulator. At the end of a lever 64 pivotally mounted on a pin 66 is a cam 64 which engages with the edge of said material feeding plate 60. Upward or downward movement of the lever 64 changes the amplitude of the motion of the material feeding plate 60, 60'. Numeral 65 represents a scale for indicating the degree of the length of stitch and numeral 66 is a transparent cover for protecting the bobbin case from dust.

(IV) BOBBIN AND SEWING If the change-over switch 19 is placed in the BOB- BIN position, an electric current flows in the opposite direction with the result that the motor M, which is a DC. motor, turns in the opposite direction. Thus the main gear 29 rotates in the counter-clockwise direction in FIG. 4 without rotating the spindle 33, as has already been explained in Part I.

Referring to FIG. 2, a friction wheel 12' carrying a thread winder spindle 12 is biased against the side face of the main gear 29 by means of a spring 67. The friction wheel 12' is engaged with or disengaged from said main gear by moving a thread winder lever 13 in FIG. 1 down or up, respectively. The friction wheel 12, when engaged with the main gear 29, rotates in the clockwise direction in FIG. 1 if the motor M rotates in the direction of BOBBIN. Therefore, thread can be wound onto a bobbin reel if the reel is placed on the thread winder spindle 12. The thread winder lever 13 biases thread onto the reel so that it is uniformly wound up. Numeral 1 1 indicates a thread tension roller on which thread is fed.

It can be easily understood from the wiring diagram of FIG. 6 that if the actuating switch 18 is placed at the OFF position and a pedal switch 21 is connected to a pedal switch connection 20, this pedal switch 21 can serve as an on-off switch in place of the actuating switch 18.

It is advantageous that sewing materials can be handled with both hands of the operator since the present sewing machine can be remotely controlled by the pedal switch 21 placed under the foot of the operator when the machine body is set on a table by the use of a clamp 22, L-shaped bolt 23 and a butterfly nut 24 as shown in FIG. 1.

When sewing, a bed extension 2 can be supported by a stand 25. The bent edge 1' of the bed 1 engages with the bent edge of the bed extension 2' so as to form a continuous bed surf acc.

The upper thread is guided in a manner similar to that of a common real sewing machine from a thread spool 7 through a thread guide 6, a tension adjusting means 10', the thread take-up lever 9, a thread take-up spring 15 and into the hole of the needle :16.

The sewing machine of the present invention has novel and suitable mechanisms for a toy machine, the motions of all the parts necessary for sewing being carried out completely and with the advantages of being strong, noiseless during the running of the machine and being manufactured at low cost.

Since many changes could be made in the above construction of the toy sewing machine and many apparently widely difierent embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. A toy sewing machine having a bed, a head mounted on the bed, a spindle horizontally positioned in said head, a hand wheel connected to said spindle, a direct current electric motor, a transmission system drivingly connecting said spindle and the electric motor, a free-wheeling mechanism provided between said spindle and said transmission system, a horizontal shaft positioned below the bed, means drivingly connecting the horizontal shaft and said spindle, a needle rod driven by said spindle to reciprocate up and down and carrying a needle at its lower end, and a bobbin case mounted on said horizontal shaft and moving relative to said needle, whereby the sewing machine can be operated either by hand through 6 said hand wheel or by electricity through said electric motor.

2. A toy sewing machine having a bed, a head mounted on the bed, a spindle horizontally positioned in said head, a hand wheel connected to said spindle, a direct current electric motor, a transmission system drivingly connecting said spindle and the electric motor, a horizontal shaft positioned below the bed, means drivingly connecting the horizontal shaft and said spindle, a needle rod driven by said spindle to reciprocate up and down and carrying a needle at its lower end, a bobbin case mounted on said horizontal shaft and moving relative to said needle, a changeover switch coupled to said motor changing over said electric motor to rotate positively or reversely, and a free-wheeling mechanism provided between said spindle and said transmission system, whereby the spindle rotates in the desired direction when the electric motor rotates in the positive direction, and the spindle does not rotate when the motor rotates in the reverse direction.

References Cited UNITED STATES PATENTS 865,149 9/1907 Ammerman 112l82 1,738,672 12/1929 Saurman 112-219 2,919,666 1/1960 Winz 112219 2,920,221 1/1960 Schwab 112-219 X PATRICK D. LAWSON, Primary Examiner. J. R. BOLER, Assistant Examiner. 

